Murrv

root@bandit-db:~$ cat description.txt

A Bandit MIRV grenade that splits into several child grenades on detonation. The exact child count depends on its rolled parts, and every child inherits the parent grenade's base damage and element, so overlapping hits can stack into heavy burst damage. Unlike the Torgue version, it can roll in any element.

root@bandit-db:~$ cat notes.txt

It can appear under names such as Mrvur, Mruv, Muvr, or Muvv. All of them are intentional misspellings of MIRV.